By Wayne ParryATLANTIC CITY, N.J. -- Here's how bad things have gotten for Atlantic City's 11 casinos: Even a revenue decline of nearly 10% looks pretty good right now. That's how much less the casinos won from gamblers in October compared with a year ago. Though still high, the 9.9% decline actually represents progress when compared with the 15.1% plunge revenue took in September -- the biggest one-month decline in the 30-year history of casino gambling in Atlantic City. "I truly don't think we've seen the worst yet," said J. Carlos Tolosa, Eastern Division president of Harrah's Entertainment ( HET), which owns four casinos here. The company has already laid off several hundred workers this year and may have to let even more go if things don't improve, he said. The casinos must deal with stiff competition from out-of-state slots parlors, which are stealing Atlantic City's most reliable customers, and the worsening economy, which is leaving the remaining ones less money to gamble with. For the month, casinos won $346.3 million. Slots revenue was $235.9 million, down 12.7%, while table games revenue was $110.3 million, down 3.3%. "These are dismal numbers," Tolosa said. Eight of the city's 11 casinos posted double-digit declines, and only two showed an increase. The worst performer was Trump ( TRMP) Marina Hotel Casino (down 29.3%), followed closely by Resorts Atlantic City (down 28.7%), and its sister property, the Atlantic City Hilton ( HLT) Casino Resort (down 21.4 percent).